I was wondering this myself, since I have literally over a dozen of these in my backyard (I’m in Glen Park). I believe this species is a Cross Orbweaver – http://bugguide.net/node/view/3376, but I would love a true expert to identify it.

I read somewhere that an orbweaver is given its name based on the shape of its web, but I would argue that it has something to do with the way it eats. I got to watch a wrestling (should that be in quotes?) match between two of them, just outside my window, and then all of a sudden one spider started wrapping the other spider up in a lot of web and created a little ball, and then, I presume, it liquified the insides and ate them. Let’s see if I can find the video I took of this happening. I didn’t get the whole event, it took a while, but I think I got part of it.

Here’s a decent source for identifying neighborhood spiders: http://www.sfbaywildlife.info/species/spiders.htm . Top photo looks to be a Western Spotted Orbweaver, bottom photo is clearly a Cross Orbweaver. Orbweavers make up about 99% of the spiders we see in our yard, so it’s generally a good guess in Bernalwood!

Found the footage I took. My first time using iMovie to put a bunch of shorter videos together into one long one, so apologies for lack of more editing, image quality, and my commentary (dunno how to take that out or change it, oh well). This was from Oct 15, 2009

Here’s a nice blog post about this Araneus diadematus from my pal JD:http://endless-swarm.com/?p=507
Very informative and well-written.
“Here in the Bay Area, we have very few really large insects. Aside from Jerusalem crickets, most insects and spiders here are small and scarce. But in September and October, the weather heats up, and beautiful huge orb weavers appear out of nowhere, and get big. They are the heralds of Autumn known as Araneus diadematus….”

I’ve had a number of these taking over my somewhat neglected yard the last month or two. I’ve mostly been letting them be as long as they spread their webs in areas I won’t run into them, as theoretically they should cut down a bit on the populations of some other pests (my biggest annoyance is the light-brown apple moth).

I read this article about Orb Spiders back in September AKA “Charlotte’s Web” spider. We used to get them down in Venice Beach as well. Our Bernal yard has been boobie-trapped with these suckers for the last couple of months. My neighbors must think i’m crazy – I scream every time I walk through a web!.

Apparently, they’ll die off around November, …after they’ve laid the eggs for the next generation of spiders. Then they’ll be back next September.

From the Article:
“Vetter said the venom of the orb weaver isn’t toxic for humans, so they pose no real danger, even though they might be a nuisance.

“It’s annoying to run in to the webs,” said Vetter. The spiders are “big enough that if they bit you, it’d be painful from the mechanical piercing of the skin.”

Here’s the LA TImes Article:
“http://latimesblogs.latimes.com/lanow/2011/09/spiders-nuisance.html